The Prohibition of Usuary for Consumers and Producers
Some western economists make a distinction between usuary on consumer loans and usuary on loans for commercial enterprise, claiming that it was necessary to prohibit usuary in the past, but now it is necessary to permit it, because loans were used to be taken in the past for purposes of consumption, whereas now they are taken for purposes of production. This is a deceptive distinction, because if the usuary was extracted on a consumer loan, the loan was taken by the consumer to spend on some of his necessities, so it is not permissible for him to pay back an extra percent on his debt, rather it is enough for him to repay the original debt when he is able.
And if the loan was taken for investment in a commercial enterprise, the profit of that enterprise is due to the effort expended by the borrower and not the capital of the loan, because capital by itself will never produce an increase without accompanying human effort.